History of the Typewriter

—310— cause electrical pulsations upon the connecting wire, which pulsations are recorded on the receivers by special electro- magnets actuating steel pens which trace corresponding spirals upon the recording papers. These spirals broken into dots similar to the waxed depressions in the zinc plate, build themselves up automatically and the pictures unfold gradually, being composed of thousands of dots. An exact copy is thus made of the zinc plate which in itself is a perfect half-tone of the original picture when completed. The transmitting operator then opens his key, stopping all the machines on the line. The electrograph is reversible, that is, the machine is either a transmitter or a receiver. The simple changing of a switch and substitution of a pen for the stylus makes the change. Sitting at his machine the receiving operator sees the face before him develop in a few moments from an imperfect outline to a human likeness which is startling. The effect is somewhat similar to the development of a photographic negative, pens acting instead of the chemicals. The electrograph has been operated over lines ranging from a few miles to 1,100, portraits being transmitted the longer distance successfully. An idea of the value of the apparatus for news service can be gained when it is stated that the Washington correspondent of a metro- politan daily paper, for instance, can keep one wire “ hot ” with the text of an interview or an account of some sensa- tional episode, while, by another, he is transmitting portraits of persons prominently concerned and photographs of scenes connected with the story. Yetman’s Transmitting Typewriter. This machine was launched upon the American market about the yeai 1903, and was the invention of Mr. Charles E. Yetmun. Very great things were expected of the instrument, which took many years to invent and bring to perfoction, but it had not a very extended commercial career before the Company which exploited it fell into difficulties, and before its affairs could be straightened out, the president of the Company was found dead under the most singular circum- stances__it being, to this day, unsettled whether he fell by his own hand, or by that of the assassin. The Yetman machine is a typewriter of the front strike variety, and the following description, quoted from The Telegraph Age, will convey a fair and accurate idea, of its construction and scope.